Hard facing alloys



United States Patent HARD FACING ALLOYS Arthur T. Cape, Los Angeles, Calif., assignor to Coast Metals, Inc., Little Ferry, N. J., a corporation of Delaware No Drawing. Application November 2, 1954, Serial No. 466,430

1 Claim. (Cl. 75126) This invention relates generally to hard facing alloys, but has reference more particularly to alloys of this type which are abnormally hard for the carbon-chromium range which they cover.

In accordance with the invention, the alloys fall within the following ranges:

Examples Range Carbon. percent. 1-4. 5 4. 25 4. 25 l. 25 1. 75 Chromiurm 1727 23 23 23 23 Molybdenum do. 4-10 8 8 8 8 Cobalt -do 5-25 10 10 10 10 Silicon -.do Up 1.04 None 2 None None on do Balance Bal. Bal. Bal. Bal

Hardness (Rockwell G The alloys, as noted, are essentially 23% chromitun,

Patented July 30, 1957 ice iron-base alloys, with molybdenum and cobalt in the stated ranges.

The Knoop hardnesses of these alloys are high, ranging from about 650 at the lower end of the range up to about 1050 with the silicon-containing variety.

The low carbon alloy, i. e., Example 3, is surprisingly hard, having a hardness of 48/53 Rockwell C scale, yet is machinable and highly resistant to heat checking when used for high temperature purposes. It out-performs cobalt-base chromium-tungsten alloys as a roller guide in rolling mill applications. In other words, it takes high loads at high temperature, withstands changes in temperature, and wears well.

It is to be understood that the expression the remainder being substantially iron, as used in the claim, is to be construed as including any other ingredients or impurities in relatively small or trace amounts, which are found associated with the various constituents of the alloy.

Having thus described my invention, I claim:

A hard facing alloy having a Knoop hardness of from about 650 to about 1050, said alloy consisting of carbon in amounts of from about 1 to about 4.5%, chromium in amounts of from about 17 to about 27%, molybdenum in amounts of from about 4 to about 10%, cobalt in amounts of from about 5 to about and silicon up to about 4%, the remainder being substantially all iron, said alloy being substantially free of tungsten.

References Cited in the file of this patent FOREIGN PATENTS 678,449 Great Britain Sept. 3, 1952 

